There exists an Open authentication (OAuth) protocol (see OAuth Specification 1.0 available at http://oauth.net/license/core/1.0) to handle user credentials between multiple parties on the web. Further, there exist a number of token-based sharing solutions that enable content sharing between web entities similar to the before mentioned OAuth system. For instance, Facebook, Flickr, Google, Smugmug and Photobucket all use tokens for authentication.
PeCMan is a web-tool that organizes a user's content (see http://www.pecman.net/). A schematic view of the PeCMan architecture is depicted in FIG. 1. Users can for example upload URLs in PeCMan, semantically tag the information with free-format tags and later find that information back by querying PeCMan with the same tags. Since multiple URLs can be tagged with the same tags, PeCMan enables a user to organize all objects that are kept on a plethora of storage providers (e.g. web servers, home stores or mail servers) through one logical location akin a “virtual drive”.
PeCMan recognizes three kinds of references: public, private non-shared and private shared content. Public content are URLs pointing at publicly available web sources. Accessing such content does not require user credentials, which implies that one can easily share such content with whomever is interested in that content. When public information is shared between users, PeCMan simply sends the requested URLs directly to the requesting or secondary PeCMan client and the secondary PeCMan client retrieves the content through e.g. WebDAV or HTTP.
Private content is typically content that can only be accessed through a secured location, typically a secured website (i.e. storage providers). To access secured storage providers 7, a web client 3 first establishes a secure connection e.g. through SSL/TLS, and then provides the user credentials (typically a user-ID and password) to authenticate the user. After a user is authenticated, a web client 3 can access privately stored content. Typically inside the addressed web server 7 a state is allocated that is associated with the communication channel. This state indicates to the web server 7 that the requesting web client 3 has authenticated itself.
Some devices that can be used to render or play this privately stored content don't have the capability to request users for credentials and to set up a secure session with the media server.